This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Examination of the ecology complemented with functional genomics of endocrine disruption in a salamander will allow development of an amphibian ED bioassy system that can be used in human environmental health policy. Use of microarray analysis and subsequent in situ hybridization can identify differential gene expression associated with atrazine exposure. When this genomics approach is complemented by ecological manipulations of a broad array of conditions, it allows for identification of a likely set of hypotheses for what conditions are resulting in ED-mediated up- and down-regulation of genes. Atrazine and estrogen have obvious effects on sexual maturation, but also interact with the hormones that regulate amphibian metamorphosis. The work described in this proposal is designed to test the hypothesis that the action of two endocrine disruptors (atrazine and estrogen) found commonly in the environment will interact with the normal ecological cues experienced by larval salamanders. The result of such interactions of EDs and ecology will be larger-than-expected effects of sub-lethal concentration of EDs on mortality, growth and metamorphic and sexual development of the larval salamanders.